Space discharge device



June 29 1926.

F. s. M CULLOUGH SPACE DISCHARGE DEVICE Filed Dec. 11, 1922 I INVENTOR Pvedevick S. McCuHouSh BY 4 ATTORNEY Patented June-29 1926.

UNITED STATES PATENT OFFICE.

sPAcn DISCHARGE DEVICE.

Application filed lnecember 11, 1922. Serial No. 606,348.

' ferent temperatures for effecting rectification of alternating currents.

The present invention proposes to provide a space discharge device having'points between which there is a relatively great difference in temperature for producinga potential drop between such points for the purpose of rectifying alternating currents of extremely high frequency while eliminating corona and brush effects.

. The invention is applicable todevices in which the power is dissipated in the device, or to a device for supplying such rectified currents to external circuits. J

The invention may be understood by reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of a space discharge device of a type inwhich the power. is dissipated in the tube itself;

Fig. 2 is a similar view of a device wherein the rectified current is conducted toan external circuit. I

In Fig. 1, 5 designates an evacuated vessel of suitable material, such as glass, around which are several turns of a conductor, form-.

ing a coil designated 6. This coil is connected with a source of high frequency alternating current, preferably a source of current alternating at radio frequency, not shown.

Within the vessel 5 isa coil 7 having the through coil 6, an electro-magnetic field will be produced within the tube. This will induce a current in the closed circuit Including turns of wire 9 and reslstance element 8,

causing the latter to be heated. At each .half cycle of the alternating field, terminal 10 will be positively charged and element 8 will have a ne ative potential, whereupon,

due to the di erence in temperatures, terminal 10 being cold, a current will flow from the terminal 10 or anode to the resistance element 8 or cathode. When the field has reversed, and terminal 10 has a negative potential and element 8 is positive, no current will flow between these points. Rectification will thus be effected.

By reason of the coil 7 being disposed in a vacuum, currents of extremely high potential may be induced therein without interference by brush or corona discharges. Very high frequencies may thus be obtained. It will be seen that no wires enter the vessel in this construction.

Since the current changes in the coil are of 'very great frequency, the potential difi'erence developed between the cathode 8 and the anode 10 are very great, especially since this anode is connected to that end of the coil 7 remote from the coil 9. Electrons, therefore, hit the anode 10 with great velocity and X-rays are generated at this anode. The tube, therefore, may be employed as a source of X-rays. Since the target 10 is of apparently small area, the stream of X-rays produced is concentrated.

In the device shown in Fig. 2, the same principle, i. e., rectification across the terminals of a coil. is e ected. In this figure, 12 is an evacuated vessel having a closed metallic circuit therein which includes a loop 13 and a. high resistance element 14.

A coil 15 is placed in the vessel around the high'resistance element 14:, and this coil is connected with a source of radio-frequency currents,.not shown. A conductor 16 serves to connect the loop 13 with one side 17 of the line to coil 15, and an ammeter is shown in this circuit between the loop and the line. Other devices than an ammeter may,

'of course, be connected in this circuit.

The radiofrequency currents in coil 15 serve to induce an alternating current in 13 and resistance 14, heating the latter. When element 13 lias become heated to a relatively high tem erature, a direct current will flow through t e ammeter circuit at extremely high voltages at everypositive half cycle of point A of coil 15. .During the other half cycle, when point-A is negative, no current will flow. Rectification is thus effected.

Because the potential is built up in a vacuum, currents of extremely high voltage may be reached without corona effects and brushmg. Y

The hot body 14 may serve as a cathode means also derivlng energy and the loop 13, being cold, may serve as an anode so that X-rays are developed in this tube in a way similar to that explained in connection with Fig. 1. Since the rectangle 13 is of considerable area, the X-rays produced in this way are not confined to a small beam and the tube may be uscd'when a distributed radiation is required. The tube shown in Fig. 2 may also be used as a rectifier, direct current being produced from alternating. as already explained.

Obviously, various changes and modifications may be made in the device, it being understood that the drawings and description are merely illustrative of my invention.

What I claim is:

1. A space discharge device comprising an evacuated vessel having means wholly within said envelope for building up currents of high potential from energy supplied by means outside said envelope, an means in the vessel for effecting rectification of such currents.

2. A space discharge device comprising an evacuated vessel, a coil through which radio frequency alternating currents may be passed, and means deriving energy from this coil for efiiecting rectification of the currents which are supplied to the coil.

3. A space d'scharge .device comprising an evacuated vessel, a coil associated with the vessel through which high frequency currents constituting the energy to be rectified are passed, means in the vessel for rectifying alternating currents, said means deriving the energy to be rectified from said coil, said means including a hot cathode and from said coil for heating the cathode.

4. A space discharge device comprising an evacuated vessel, a coil in the vessel, and means for establishing a temperature difference between opposite ends of the coil to enable a space current to flow from the cold to the hot ends when the cold end has a ositi-ve potential, whereby rectification of alternating currents may be effected.

5.. A space discharge device comprising an evacuated vessel, a coil associated with the vessel adapted to receive energy alternating at high frequencies, a cathode in the vessel comprising a high resistance element in a closed circuit, which circuit derives energy for heating the cathode from high frequency alternating currents in the coil by inductance, and a circuit including the cathode for receiving and rectifying energy from the coil.

6. A space discharge device comprising an evacuated vessel, a coil for connection in a radio frequency current associated with the vessel, a coil within the vessel in transformer relation to said first named coil, a hot cathode connected with one end of the last named coil, an anode connected with the other end of the coil.

7. A space discharge device comprising an evacuated vessel, a coil for connection in a high frequency current surrounding the vessel, a second coil within the vessel in inductive relation to the first coil, a cathode connected to one end of the coil, an anode at the other end of the coil, and means for heating the cathode, whereby a current may flow in one direction between the anode and cathode when the latter is heated, said device enabling a high frequency current to be built up and dissipated in the vessel without brushing or corona effects.

8. A space discharge device comprising an evacuated vessel, a coil for connection in a high frequency current surrounding the vessel, a second coil within the vessel in inductive relation to the first coil, -acathode at one end of the coil, an anode connected to the other end of the coil, and means IfOI' heating the cathode including a closedkcircuit in inductive relation to said first coil inwhich heating currents for the cathodemay be induced, whereby a current may flow in one direction between the anode and cathode when the latter is heated, said device enabling a high frequency current to be built up and dissipated in the vessel without rbrushing or corona effects.

9. A space-discharge device comprising elements within an evacuated vessel and means for impressing alternating energy thereon, the elements within the vessel in cluding means for producing currents of extremely high potent-ialfrom said alternating energy means and for rectifying said currents. V

10. A space discharge device comprising an evacuated vessel having means therein for building up and rectifying currents of extremely high potential, said means including a cathode adapted to be heated by the passage of induced currents therethrough, and a coil having cathode, and a single coil outside the ves-. sel for inducing currents to berectified in the coil and for inducing heating currents in the cathode.

In testimony whereof, I havel hereunto subscribed my name this 7th dayof December 1922.

FREDERICK S. MOCULLOUGH.

one-end connected with the. 

